Officer Gregory Laidler, 31, was working a drug sting operation late Wednesday night on a street in Miami's Liberty City neighborhood.

An officer from the Florida Department of Law Enforcement, planted to catch police officers suspected of ripping off drug buyers, went undercover with $110 in marked money. He bought $10 worth of marijuana from Laidler and paid him with a $20 bill.

Laidler then arrested the undercover FDLE agent and confiscated all the man's money, police said.

Police said Laidler turned in the $20 bill and two $5 bags of marijuana and left for the night. Two officers from the Miami police internal security unit followed Laidler and arrested him Thursday on Interstate 95. They found the other $90 in Laidler's car.

Laidler was charged with petty theft and official misconduct and was relieved of duty with pay.

''An investigation had been going on since the beginning of June due to allegations of missing money made by people arrested in stings,'' said Officer Reginald Roundtree. ''Laidler was involved in all the arrests.''

Laidler has received nine commendations and one reprimand during his four years with the department. The reprimand stemmed from his arrest a year ago by Hollywood police on charges of resisting arrest, loitering and prowling at a Hollywood park. He was acquitted in October.

Hollywood police spokesman Jim Rabbit said Laidler and John Edward Harris, the starting safety for the Seattle Seahawks football team, were hanging around the park and a man thought they were going to rob him.

Rabbit said Laidler protested that he was being harassed because he was ''a black guy in a white park,'' and according to police reports did not identify himself to police or say what he was doing in the park.